Answer: 693 years
Step-by-step explanation:
Expression for rate law for first order kinetics is given by:

k = rate constant
t = time taken for decomposition = 1
= Initial amount of the reactant
= amount of the reactant left =



for half life : 

Putting in the values , we get


Thus half life of this isotope, to the nearest year is 693.
Put the decimal over 100 and get rid of the decimal
Answer:
Step-by-step explanation:
1.Categorize Your Data. Compile your data into categories. ...
2.Find the Total. Add all the numbers together to get the total. ...
3.Divide the Categories. Divide each of the categories by the total. ...
4.Convert to Percentages. Multiply each of the decimals by 100 to get the percentages. ...
5.Calculate the Degrees.
They are algebraic symbols or known as unknown number. There is no true value for them. The value of algebraic symbols are based on equations
ie. 1+x = 2
First, we isolate the x by canceling the +1 FROM BOTH SIDES(Balance method) by -1 ON BOTH SIDES.
1+x-1 = 2-1
So we are left with the x on the left side, and a single number on the right side. Therefore, our calculation is complete.
x = 1
More complex cases would be
2y-3 = 45
First, we need to isolate the algebraic symbol, which is 2y (yx2) by +3 ON BOTH SIDES
2y-3+3 = 45+3
2y = 48
WE ARE NOT DONE! 2y=48 is still an equation. Therefore, to isolate the y, we need to divide BOTH SIDES by 2
2y/2 = 48/2
y = 24
There is no true or absolute or definite value for algebraic symbols like x,y,z,a,c,t,h,d etc. They are used to represent unknown numbers.
Hope this helped!
I don’t bro cuz I need help to